The proposed research project aims at studying four types of 15-hydroxyprostaglandin dehydrogenases and two types of ketoprostaglandin reductases. The 15-hydroxyprostaglandin dehydrogenases control the biological inactivation of prostaglandins, whereas the 9-keto-prostaglandin reductase regulates the interconversion of functionally different prostaglandins and the 15-ketoprostaglandin reductase catalyzes the reactivation of some inactive prostaglandin catabolites. Several aspects of research on these enzymes will be investigated. The include: (1) purification and characterization (2) regulatory properties (3) antibody production (4) development of radioimmunoassay (5) possible roles in genetic hypertension. Purification of these enzymes from swine kidney and human placenta will employ various fractionation techniques, isoelectrofocusing and affinity chromatography. Some physicochemical properties will be studied by established methods. The role of cyclic nucleotide dependent protein kinases in the regulation, in particular, of 9-ketoprostaglandin reductase will be investigated. Generation of antibody against Type I 15-hydroxyprostaglandin dehydrogenase will be achieved by repeated immunization of the rabbits with the enzyme. The use of antibody in the development of radioimmunoassay for the enzyme in studying immunological differences of the enzyme in various tissues and animal species will be explored. Possible changes in catalytic and immunological properties of the enzyme in genetic hypertensive rats will be elucidated. Similar immunological studies will be carried out with other types of prostaglandin dehydrogenases and reductases.